Let's say you want to "break" all remote access capabilities on your rooted Android phone and your Windows PC. What do you do or delete so remote access is truly broken and can't be used (by a hacker)?
I don't see much of a difference with your previous question How to close or block remote access backdoors? except that it now a bit more focused by asking only for Windows and Android.
It looks like you are not asking about disabling explicitly implemented remote access functionality but anything which might allow an attacker to allow remote access. Since this might also include bugs in the firmware and drivers the only way to disable remote access is to disable any network connectivity at all, i.e. disable network interfaces and/or put the device in some Faraday cage or similar. This includes everything which might be reachable by the hacker you envision, i.e. Ethernet, WiFi, Bluetooth, USB based networking and maybe even NFC.
Of course, this makes the devices kind of unusable for most modern use cases. Given that it may be questionable if it makes even sense to harden an existing device/OS this way, or if is better to use some more specialized device with a smaller attacker surface for this specific use case instead.